A few very minor things that I noticed:
1. You use pre-increment in "for" loops (e.g. FastPathGrantLock). The
rest of the code seems to use post-increment in "for" loops, so you
might as well stick to the convention in cases where the two have
identical meaning.
2. Typo in the README: "acquire the every" should be "acquire every".
3. Typo in comment in lock.c: "last because most" should be "last
because it's the most". (I just realized that's actually not your typo,
so fixing it is optional).
Regards,
Jeff Davis